[SCSI] tgt: use scsi_init_io instead of scsi_alloc_sgtable

If we export scsi_init_io()/scsi_release_buffers() instead of
scsi_{alloc,free}_sgtable() from scsi_lib than tgt code is much more
insulated from scsi_lib changes. As a bonus it will also gain bidi
capability when it comes.

[jejb: rebase on to sg_table and fix up rejections]

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 5 insertions, 23 deletions

diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c
index 01e03f3f6ffa..91630baea532 100644
--- a/drivers/scsi/scsi_tgt_lib.c
+++ b/drivers/scsi/scsi_tgt_lib.c
@@ -331,8 +331,7 @@ static void scsi_tgt_cmd_done(struct scsi_cmnd *cmd)
 
         scsi_tgt_uspace_send_status(cmd, tcmd->itn_id, tcmd->tag);
 
-        if (scsi_sglist(cmd))
-                scsi_free_sgtable(cmd);
+        scsi_release_buffers(cmd);
 
         queue_work(scsi_tgtd, &tcmd->work);
 }
@@ -353,25 +352,6 @@ static int scsi_tgt_transfer_response(struct scsi_cmnd *cmd)
         return 0;
 }
 
-static int scsi_tgt_init_cmd(struct scsi_cmnd *cmd, gfp_t gfp_mask)
-{
-        struct request *rq = cmd->request;
-        int count;
-
-        cmd->use_sg = rq->nr_phys_segments;
-        if (scsi_alloc_sgtable(cmd, gfp_mask))
-                return -ENOMEM;
-
-        cmd->request_bufflen = rq->data_len;
-
-        dprintk("cmd %p cnt %d %lu\n", cmd, scsi_sg_count(cmd),
-                rq_data_dir(rq));
-        count = blk_rq_map_sg(rq->q, rq, scsi_sglist(cmd));
-        BUG_ON(count > cmd->use_sg);
-        cmd->use_sg = count;
-        return 0;
-}
-
 /* TODO: test this crap and replace bio_map_user with new interface maybe */
 static int scsi_map_user_pages(struct scsi_tgt_cmd *tcmd, struct scsi_cmnd *cmd,
                                unsigned long uaddr, unsigned int len, int rw)
@@ -397,9 +377,11 @@ static int scsi_map_user_pages(struct scsi_tgt_cmd *tcmd, struct scsi_cmnd *cmd,
         }
 
         tcmd->bio = rq->bio;
-        err = scsi_tgt_init_cmd(cmd, GFP_KERNEL);
-        if (err)
+        err = scsi_init_io(cmd, GFP_KERNEL);
+        if (err) {
+                scsi_release_buffers(cmd);
                 goto unmap_rq;
+        }
 
         return 0;